The present invention relates to telecommunications and networking, and more particularly to computer program products, related methods, and a protocol for interworking services between public telephone networks, Intelligent Networks, and internet protocol (IP) networks.
Telecommunications originated over a century ago using traditional landline based telephony technology. Over time, standards, protocols, and topologies were developed and optimized to provide telephony services. More recently, wireless telephony was developed as an alternative means of telecommunications. Wireless telephony evolved with its own separate and distinct standards, protocols, and topologies optimized for the mobile telephony environment. The SS7 (Signaling System 7) network was developed to provide digital out-of-band signaling channels for both the landline and wireless telephone networks. The modern public telephone network (PTN) leverages SS7 capabilities to establish telephone call connections and provide advanced services, such as 800 or toll free, calling card, Intelligent Network services, Call Back, Calling Name Delivery, Local Number Portability and wireless roaming services. Further, new architectures and interfaces have been developed recently that permit further integration and cooperation between landline and wireless telephony networks. It has been proven advantageous to share resources and provide PTN services more generically, without being concerned whether the telephone terminals involved in the communication are landline or wireless.
IP networks (including the public Internet) developed in parallel with the converging landline and wireless telephony infrastructures. While the function of the PTN network was primarily to provide end-to-end connections between telephone service subscribers, IP networks were developed to interconnect and leverage the information and processing capabilities of millions of networked computers. Given the substantially more complex purpose of an IP network, it evolved as a separate network infrastructure with distinct protocols optimized for the functions to be provided.
Over time, the functions provided by the PTN network have become increasingly more sophisticated. Therefore, it is not surprising that cooperation between an IP network and a PTN network is desired, and in some instances, required. For example, it would be advantageous to provide services to the PTN network from the vast resources resident on an IP network. In this regard, one early application used the Internet to setup a connection and establish a voice telephone call. An IP telephone call can be originated from any telephone terminal, such as a conventional telephone terminal or an appropriately equipped computer connected to an IP network, and placed to another telephone terminal, such as any other conventional telephone terminal or another appropriately equipped computer connected to an IP network. While this capability is useful, the IP telephone calls are only capable of establishing an end-to-end connection across an IP network. As such, no other services or applications can cross the IP network and PTN network border, although the need for doing so persists.
The IETF (Internet Engineering Task Force) is an open international community of network designers, operators, vendors, and researchers concerned with the evolution of the Internet architecture and the smooth operation of the public Internet. The actual technical work of the IETF is done in its working groups, which are organized by topic into several areas (e.g., routing, transport, security, etc.). Much of the work is handled via email mailing lists and electronic document submissions. Proposals are discussed, evolved, and implemented if advantageous. Proposals have been submitted attempting to converge the capabilities of the IP networks and telecommunication networks. In services interworking for IP telephone calls, one submitted proposal suggests encapsulating the SS7 protocol stack from the link layer to the above layers, including the MTP level 2 and level 3 layers, the SCCP layer, and the TCAP layer. Another proposal suggests encapsulating the SCCP layer and the above layers in the SS7 protocol stack. However, neither proposal properly addresses differences in the addressing and routing functions as implemented in the IP networks and the PTN networks. In addition, neither proposal defines a convergent protocol between these diverse networks. At best, these proposals might ultimately provide transport on an IP network between two PTN networks.
However, in order to effectively converge and leverage these distinct networks, true interworking is required. Interworking refers generally to transporting a message between a first network entity executing a software application program in a first network domain and a second network entity executing a software application program in a second network domain. In other words, interworking refers to exchanging messages between software application programs executing in different network domains. The above proposals fail to provide exchanges of PTN messages, such as TCAP (Transaction Capabilities Application Part) messages, between entities in different networking domains, such as an IP network and the PTN network. Accordingly, a TCAP application executing in an IP network and a TCAP application executing in a PTN network typically cannot exchange TCAP messages, cannot exchange telephony services, and cannot interwork effectively.
As such, a need exists for a fully functional interworking solution between an IP network and the PTN network to preserve the transparency of TCAP messaging in the PTN networks while the TCAP messages are routed to or from IP networks. Further, a need exists for a communication protocol and supporting methods for effectively transporting TCAP messages between a public telephone network and an internet protocol network. Were these needs met, telephony based services could be provided from a public telephone network, an IP network, or both, as desired. A number of other advantages would also likely emerge from providing fully functional interworking between an IP network and a public telephone network, as was observed from the convergence of the landline and wireless network infrastructures.
The present invention provides a protocol, computer program products, and related methods for supporting services interworking between an IP network and a public telephone network, including the Intelligent Network and wireless networks. As such, the present invention addresses at least some of the above needs while providing some advantages. According to the present invention, conventional TCAP messages from the public telephone network can be exchanged with encapsulated TCAP messages in an IP network. The protocol, computer program products, and related methods of the present invention cooperatively support exchanging encapsulated TCAP messages in the IP network. Computer software application programs executing in network nodes disposed in an IP network and in a public telephone network can thereby cooperatively process information and exchange services therebetween. Existing services can be provided to telephony services subscribers, while new services could be developed by leveraging the processing capability of network nodes in an IP network, according to the present invention.
In one embodiment, the present invention provides a Simple TCAP-IP Interworking protocol (STIPP), represented as a computer data signal embodied in an electrical signal represented as a plurality of bits, for exchanging an encapsulated message between two internet protocol entities. The computer data signal comprises an internet protocol portion, a transport portion, and a STIP (Simple TCAP Interworking Part) portion. The internet protocol portion supports physical layer functions, datalink layer functions, and network layer functions compatible with an internet protocol network. The transport portion is operably connected to the internet protocol portion and serves to support transport layer functions compatible with an internet protocol network. Lastly, the STIP portion is operably connected to the transport portion, and is adapted to exchange the encapsulated message between two internet protocol network entities, such that services interworking is supported therebetween.
Various embodiments of the protocol, or computer data signal, according to the present invention further define the STIP portion. In one embodiment, the STIP portion comprises an STIP header for transporting an encapsulated message therein. Further, the STIP portion may comprise various fields, such as a version field for identifying the version of the STIP portion to at least one internet protocol network entity. In addition, the STIP portion may comprise a message type field, such that the type of message may be identified to at least one internet protocol network entity. The message type field may comprise at least one protocol message type selected from the group consisting of a login message type, a login acknowledgement message type, a security packet message type, and a status message type. In addition, the message type field can comprise at least one data message type selected from the group consisting of a TCAP data message and a TCAP data error message.
The STIP portion can also comprise at least one attribute field, such that information relating to the type of the message may be provided to at least one internet protocol network entity. Further, each attribute field may further comprise a type subfield, so that information relative to the type of attribute may be provided to at least one internet protocol network entity. The type subfield may also comprise one or more parameters selected from the group consisting of a system name, primary/backup system identifier, subsystem number, address mapping option, message encryption index, TIPG status, IP entity status, additional status, protocol type identifier, IP address, calling/called party address, sequential number identification value, and an error reason. In addition, each attribute field can further comprise a value subfield, such that information relative to the attribute may be provided to at least one internet protocol network entity. Each attribute field may also further comprise a length subfield, so that information relative to the length of the value subfield may be provided to at least one internet protocol network entity. Accordingly, the STIP portion can further comprise a data field, such that an encapsulated data and/or command message may be exchanged between internet protocol network entities. The data field may comprise an encapsulated TCAP message so that encapsulated TCAP messages may be exchanged between internet protocol network entities.
In one embodiment, the present invention further provides a computer program product for an interworking gateway exchanging TCAP messages in an SS7 protocol format with a public telephone network, and exchanging encapsulated TCAP messages in an IP format with an internet protocol network. The computer program product is executable by a processor, and comprises a computer readable storage medium having computer readable program code means embodied therein. The computer readable program code means comprises several computer instruction means. As such, computer instruction means for receiving a TCAP message in the SS7 protocol format from the public telephone network and extracting the TCAP message and associated addressing and routing information therefrom are provided. Further, computer instruction means for converting the associated addressing and routing information for the IP format and encapsulating the TCAP message in the IP protocol format with the converted addressing and routing information are provided. In addition, computer instruction means for transmitting the encapsulated TCAP message with the converted addressing and routing information to the internet protocol network for delivery to an IP network entity therein are also provided.
In an additional embodiment, the computer readable program code of the computer program product further comprises computer instruction means for receiving an encapsulated TCAP message in the IP protocol format from the internet protocol network and extracting the TCAP message and associated addressing and routing information therefrom. Further, computer instruction means for converting the associated addressing and routing information for the SS7 protocol format and encapsulating the TCAP message into the SS7 protocol format with the converted addressing and routing information are provided. In addition, computer instruction means are provided for transmitting the TCAP message with the converted addressing and routing information to the public telephone network for delivery to an SS7 network entity therein.
In a further embodiment, both computer instruction means for converting may further comprise STIP computer instruction means for processing encapsulated TCAP messages with the addressing and routing information in the IP protocol format exchanged with the internet protocol network. The STIP computer instruction means may further comprise computer instruction means for emulating SCCP flow control commands and functions for IP network entities in the internet protocol network represented to the public telephone network. In addition, the STIP computer instruction means may further comprise computer instruction means for decapsulating the TCAP message received in the SS7 protocol format from the public telephone network and encapsulating the TCAP message the IP protocol format for transmission to the internet protocol network. The STIP computer instruction means may further comprise computer instruction means for decapsulating the TCAP message received in the IP protocol format from the internet protocol network and encapsulating the TCAP message the SS7 protocol format for transmission to the public telephone network.
Further, the STIP computer instruction means may further comprise computer instruction means for interacting with the IP network entity and the internet protocol network through a STIPP protocol stack in the IP protocol format. In addition, the STIP computer instruction means may further comprise computer instruction means for performing address mapping and translation, such that the IP network entity can be addressed by a point code and subsystem number to the public telephone network and by an IP address and a port number to the internet protocol network. Still further, the STIP computer instruction means may further comprise computer instruction means for performing extended global title translations, such that a destination node in the public telephone network can be identified by at least one of a point code and optionally a subsystem number of an application entity within the destination node, and such that a destination node in the internet protocol network may be identified by an IP address and a port number. The STIP computer instruction means may further comprise computer instruction means for performing protocol discrimination for the TCAP message received from the public telephone network, so that the TCAP standard, the upper layer messaging protocol, or both, associated with the TCAP message can be identified. In addition, the STIP computer instruction means may further comprise computer instruction means for providing security functions, such as CHAP (Challenge Handshake Authentication Protocol) security functions, for authenticating the IP network entity before TCAP messages are exchanged with the IP network entity. Lastly, the STIP computer instruction means may further comprise computer instruction means for performing mediation functions to ensure that information is accessed and modified only by an authorized IP network entity or public telephone network entity.
In one embodiment, the present invention further provides a computer program product for an IP network entity exchanging encapsulated TCAP messages in an IP protocol format with an internet protocol network. The computer program product is executable by a processor, and comprises a computer readable storage medium having computer readable program code means embodied therein. The computer readable program code means comprises several computer instruction means. As such, computer instruction means for receiving a TCAP message encapsulated in the IP protocol format from the internet protocol network are provided, wherein the TCAP message originated in the public telephone network. In addition, computer instruction means for extracting the TCAP message and the associated addressing and routing information from the encapsulated TCAP message received are provided. Further, computer instruction means for processing the TCAP message originating in the public telephone network and received by the IP network entity are provided. The computer readable program code may further comprise computer instruction means for encapsulating a TCAP message in the IP protocol format for the internet protocol network, wherein the TCAP message originated in the IP network entity. The computer readable program code may also comprise computer instruction means for transmitting the TCAP message through the internet protocol network to an SS7 network entity in the public telephone network.
In a further embodiment, the computer program product may further comprise STIP computer instruction means for encapsulating and decapsulating TCAP messages with the addressing and routing information in the IP protocol format exchanged with the internet protocol network. In addition, the STIP computer instruction means may further comprise computer instruction means for interacting with the internet protocol network through a STIPP protocol stack in the IP protocol format. Further, the computer instruction means for processing the TCAP message received may further comprise computer instruction means for analyzing the TCAP message received to determine whether data incorporated therein can be processed by the IP network entity, and whether or not a data error message should be returned to the originator of the TCAP message in the public telephone network. The STIP computer instruction means can further comprise computer instruction means for providing security functions, such as CHAP security functions, to authenticate the IP network entity before TCAP messages are exchanged with the IP network entity. In addition, the STIP computer instruction means can further comprise computer instruction means for functions of the same three SCCP primitives as provided by the SS7 network to a TCAP application within the IP entity to send and receive TCAP messages.
One embodiment of the present invention provides a method for exchanging TCAP messages between a public telephone network and an internet protocol network for providing services interworking. The method according to one embodiment comprises the step of receiving a TCAP message and associated addressing and routing information in an SS7 protocol format from the public telephone network. Further, the method includes the steps of extracting the TCAP message and associated addressing and routing information from the TCAP message received, and converting the associated addressing and routing information for an IP protocol format and encapsulating the TCAP message in the IP protocol format with the converted addressing and routing information. In addition, the method comprises the step of transmitting the encapsulated TCAP message with the converted addressing and routing information to the internet protocol network for delivery to an IP network entity therein.
In another embodiment, the method may further comprise the step of receiving an encapsulated TCAP message in the IP protocol format from the internet protocol network and extracting the TCAP message and associated addressing and routing information therefrom. The method may further comprise the step of converting the associated addressing and routing information for the SS7 protocol format and encapsulating the TCAP message into the SS7 protocol format with the converted addressing and routing information. Further, the method can further comprise the step of transmitting the TCAP message with the converted addressing and routing information to the public telephone network for delivery to an SS7 network entity therein, after the transmitting step.
For one embodiment of the method, the converting and encapsulating for the IP protocol step may comprise extracting the TCAP message from the SS7 protocol format and encapsulating the TCAP message in a STIP protocol header in the IP protocol format, and the converting and encapsulating for the SS7 protocol step can comprise extracting the TCAP message from the STIP protocol header in the IP protocol format and encapsulating the TCAP message in the SS7 protocol format. In another embodiment of the method, both converting steps further comprise the step of performing at least one translation selected from the group consisting of an address translation and a global title translation on the respective TCAP message received.
In one embodiment, the present invention further provides a method for exchanging encapsulated TCAP messages with an internet protocol network, such that TCAP messages can therethrough be exchanged with a public telephone network. The method comprises the step of receiving a TCAP message encapsulated in an IP protocol format from the internet protocol network, wherein the TCAP message originated in the public telephone network. The method comprises the step of extracting the TCAP message and the associated addressing and routing information from the encapsulated TCAP message received. In addition, the method comprises the step of processing the TCAP message originating in the public telephone network and received by the IP network entity. A further embodiment of the method further comprises the steps of encapsulating a TCAP message in the IP protocol format from the internet protocol network, wherein the TCAP message originated in IP network entity, and transmitting the TCAP message through the internet protocol network to an SS7 network entity in the public telephone network. In addition, the method may further comprise the step of interacting with the internet protocol network through a STIPP protocol stack in the IP protocol format.
As such, the aforementioned protocol, computer program products, and related methods support fully functional services interworking between an IP network and a public telephone network by exchanging TCAP messages in respectively compatible formats. TCAP messages can be transported across network domains, and processed by compatible software application programs in an internet protocol network and in a public telephone network such that true services interworking can be achieved.